Derry,
Try KokaSub, Kokasub - Dive Center, they have courses in English and Spanish under request, for both recreational and technical diving. They are one of the best diving shops in Sao Paulo.
About the suit, if you dive near Sao Paulo, during summer a 5 mm wetsuit is enough. During winter I use a semi-dry suit and a hood.
Victor
Hey, Victor,
Thanks for your information! I'll contact them to check the course.
I just go through the website, I find their checkout will be in Ilha Grande. In fact, I'll go Ilha Grande during the Carnival, but just for snorkel diving and enjoy the beach